RAMADI, Iraq — Their first silhouettes appear at dusk, moving briskly under dim moonlight or the rare street lamp. Sometimes the crunch of their boots on trash-strewn streets will stir families dozing on lawns in the cool of evening.

It's another night patrol by Marines in one of Iraq's most dangerous cities.

When night falls on Ramadi, hundreds of Marines confined to bases during the day return to the streets. Daytime foot patrols are limited because of the threat of skilled snipers or roadside bombs, but the cover of darkness — and night vision technology — allows Marines to fan out into contested neighborhoods.

"We don't like going out during the day. They fight a lot more in the day," explained Cpl. Anthony Rusciano, 22, of New York, as he prepared for another midnight patrol.

In the quieter western side of Ramadi, 70 miles west of Baghdad, most night patrols are geared toward holding conversations with residents to build trust, acquire tips and erode the daytime influence of insurgents. But in other parts, such as the abandoned span of crumbling buildings that make up the city center, Marines are simply trying to keep insurgents from staging ambushes or planting more bombs.

The night also makes the summertime heat more bearable. Lugging up to 80 pounds of weapons and equipment on their patrols, sweat usually covers the Marines' faces as they speak to residents.

U.S. troops across Iraq use a common refrain — "We own the night" — to describe their edge over insurgents in darkness. But danger still lurks at night for the Marines who traverse along unfamiliar streets.

Marines sprint through lighted intersections and warily examine suspicious mounds of trash that could contain bombs. Sometimes they trip over miniature canals in the road that serve as sewers, stirring putrid fumes into the air. Roving packs of wild dogs usually announce the Marines' presence and trail closely behind.

Residents are often caught between roving insurgents in the day and the patrolling Marines at night. Though U.S. forces have recently pushed farther into the city, tens of thousands of people still live in neighborhoods that rarely see Americans.

"All the people in Ramadi are scared — scared of the mujahedeen (holy warriors), scared of the Americans," said one man to visiting Marines. Several deep gouges marked his living room wall, which he blamed on an errant U.S. grenade that tore through his home but didn't harm his six children and wife.

Many residents spoke of their desperate situations, complaining about the three to four hours of available electricity per day, the rising price of gas and water shortages.

"We need our lives back. For us, it's OK, we can deal. But our children cannot do this," said one man in his mid-30s as his young son ran around the home wearing an oversized helmet borrowed from a Marine. The man asked not to be named for fear of insurgent reprisal.

Some residents, long accustomed to Marines dropping by at odd hours, casually try to continue what they were doing. On one recent patrol, a family watched televised reports of a car bombing in Baghdad earlier that day. In a neighboring home, a heavyset man encouraged the Marines to watch the World Cup in his bedroom — in part so that he, too, could catch the last minutes of a match.

Most homes in Ramadi are surrounded by courtyard walls that provide ample cover for possible gunmen. Though a curfew reduces the number of pedestrians for Marines to monitor, they believe insurgents are always watching.

"I'm sure they were watching our movement tonight. ... I'd say within 15 to 20 minutes, everyone in the neighborhood knew we were over here. It doesn't take long for word to get around," said Cpl. Brad Bruce, 23, of LaPorte, Ind., shortly after a three-hour patrol.

Marines communicate through whispers or hand signals passed down from patrol leaders. Disciplined squads can limit their noises down to the sounds of water swishing in containers, the soft beep of their radios and the occasional Marine tripping on uneven roads.

Some homes in the city hardly seem affected by the war. Marines said on one recent patrol they found a college student reading Shakespeare's "Macbeth" — in English — as another man instant-messaged a friend on the Internet. A third young man was smoking a hookah, or a traditional Arab water pipe.

"There's some really Westernized parts here," said 1st Lt. Daniel Greene, 25, of Stafford, Va. "Sometimes I wonder what I'd feel like if a couple guys banged on my door at night and stayed for a couple days."